Решение
2.
а) (2/3)*x = - 4/5
10x = - 12
x = - 12/10
x = - 1,2
б) - (5/3) *x = 10
- 5x = 30
x = - 6
в) 0,7x = 14
x = 14/0,7
x = 20
г) 2,5x = 10
x = 10/2,5
x = 4
д) (5/3)*x = 7/3
5x = 7
x = 7/5
x = 1,4
е) (1/5)*x = 4,2
x = 4,2*5
x = 21
ж) - 0,6x = 5
x = - 5/0,6
x = - 50/6
x = - 25/3
x = - 8(1/3)
з) (2/3)*x = 4
2x = 3*4
2x = 12
x = 12/2
x = 6
3.
а) 2x + 9 = 12 + x
2x - x = 12 - 9
x = 3
б) 2x + 9 = 12 - x
2x + x = 12 - 9
3x = 3
x = 3/3
x = 1
в) 17 - 3x = 2 + 7x
- 3x - 7x = 2 - 17
- 10x = - 15
x = - 15/(-10)
x = 1,5